I am in a quandary. I really want to upgrade to a higher resolution FX body. I have a D300 and a D700 with the Nikon grip that fits both bodies. The new D800 has Megapixels out the wazoo, but a maximum frame rate of 4fps even with the optional battery grip. I shoot birds in flight as my main subject matter, so I would benefit from the high resolution of the D800, but fear the reduction of frame rate and the resultant "missed shots". Your excellent advise usually suggests analyzing what it is you shoot and base your choices on those criteria. After doing so numerous timer, I feel like their currently is no where to go. Now even the newer Prosumer Nikons have a 28+MP sensor. I sure wish Nikon made the D800 with 28MP resolution and a higher frame rate. Any comments from hi-speed shooters would be welcome. The D4 is way out of budget even if I sell both current bodies and the grip. I also considered a used D3s. That would up the frame rate even more (and the ISO), but with no better resolution than I have now.